1. Field of the Invention
The present invention relates to an image recording apparatus, and in particular, to an image recording apparatus in which a video signal representing a still picture is read out from a video signal recording medium so as to record a visualized image thereof on an image recording medium such as a sheet of printing paper.
2. Description of the Prior Art
Conventionally, there has been proposed a still image recording apparatus which receives a video signal read out from a video signal recording medium, for example, a video floppy disk, so as to reproduce a visualized image on an image recording medium such as a sheet of printing paper.
In such an apparatus, separated-color signals of red, R, green, G, and blue, B attained from the video signal read out from a video floppy disk, for example, are sequentially supplied to a recording monochromatic CRT with high brightness. In front of the display screen of the recording CRT, there are disposed a lens and a three-color separating filter such that an image displayed on the screen is projected and focused through the lens and the three-color separating filter so as to obtain a focused image on a sheet of color printing paper.
In the image recording apparatus, as described above, it is required to project the image read out from the video floppy disk and displayed on the screen of the recording CRT onto a sheet of color printing paper so as to record a color picture thereon; and to furthermore record a title, the date when the picture is shot, and other characters or letters on the same sheet.
Conventionally, in the case where such characters are to be recorded, for example, a signal representing the characters is inputted to the recording CRT together with the video signal such that when the still image is displayed on the screen of the CRT, the characters are also displayed in the neighborhood of the displayed still image; and then both of the image and the characters are projected onto a sheet of color printing paper, thereby attaining a color still image including the recorded characters. However, when the image displayed on the CRT screen is directly projected on the sheet of color printing paper, since the display position of the image obtained on the CRT screen varies depending on the thermal drift in the characteristics of the image processing circuit and the terrestrial or earth magnetic field, the location of the image displayed on the sheet of color printing paper cannot be fixed. Consequently, the image cannot be displayed at a fixed location on the sheet of color printing paper.
In addition, the contour of the image displayed on the screen of the CRT does not become a rectangular shape, namely, there is obtained a so-called barrel or spool shape. Consequently when the image is recorded on the sheet of color printing sheet, the contour of the picture is not arranged in parallel with that of the sheet of color printing paper and hence, printed picture quality is spoiled. There has been required a complex and burdensome adjustment of the CRT to remove the distortion of the contour thus appearing in the displayed image. Furthermore, straightness of the edges of the picture frame displayed on the CRT screen is insufficient, which leads to a problem that the printed picture frame does not have a smooth contour.
In order to prevent occurrences of the positional variation of the picture recorded on a sheet of color printing paper, the barrel-shaped or spoolshaped distortion of the contour of the picture, and the like, there has been employed a method in which a mechanical mask is used to shade the end portions of the periphery of the image when the image displayed on the CRT screen is projected onto the sheet of color printing paper. With this provision, regardless of the variation in position of the image displayed on the CRT, the picture can be recorded at a fixed position on the sheet of color printing paper. In addition, the occurrences of the barrel-shaped or spool-shaped distortion of the image and the like can be prevented, and consequently, the contour of the picture is arranged to be parallel to that of the sheet of color printing paper.
However, when the mechanical mask is adapted as described above, since light is interrupted on the edge portions of the periphery of the image projected onto the sheet of color printing paper, it is impossible to record letters such as of a date in the peripheral portion of the projected picture. In this situation, when letters are to be recorded, there is disposed an opening section in the mechanical mask in the neighborhood of the periphery of the image so as to arrange a lithographic film including a pattern of the letters to be recorded in the opening section, and the lithographic film is exposed to the light source so as to print the letters of the lithographic film on a sheet of color printing paper, thereby recording the letters thereon. Consequently, with this method, there has been a problem that letters other than those fixedly carried on the lithographic film cannot be printed on the sheet of color printing paper.